Deadheads. Parrotheads. Phishheads. What these cultists have in common — besides being strong advocates of altered states’ rights — is a willingness to show up at the outdoor concert ”sheds” each year, typically oblivious of whether their heroes have a new record or not. Figure in other hitless yet perennially high-grossing tourers like Neil Diamond, James Taylor, Steve Miller, and the Allman Brothers Band, and you’ve got a short list of that strangely contradictory subgenre: rockers who couldn’t sell a new record to save their lives, but whose fans will just about kill for tickets.

Winning the competition for the most wildly disproportionate ratio of ducats to new discs sold is the Grateful Dead, whose $52.4 million gross came last year despite not one studio album since 1989. And Diamond, who hasn’t gone platinum with new material since 1982’s Heartlight, grossed an astounding $29.8 million from his 1993 tour.

Tour-meister Jimmy Buffett has narrowed the gap some; last year’s Fruitcakes debuted at No. 5 before slipping off the charts five months later. But it’s still at the box office where Buffett’s cult turns out en masse, as last year’s $16.2 million tour gross confirms. Buffett says the imbalance ”used to bother me a lot more. But what’s most important is to please the Parrotheads, because there’s more to the music than just the music. It’s become a lifestyle. I wish I could take credit, but it’s fan generated. It had little to do with MCA. They just discovered I had this career, which was enlightened of them; I’ve been doing it for 30 years.”

Steve Miller says he watched his former label, Capitol, lose interest in him just as more young fans began swelling his shows, primed by classic-rock radio saturation. ”It’s like that with the Dead, too,” he bristles. ”They’d put a record out, and [the label’s] like, who cares?” With music execs earmarking promo bucks for fresher-faced acts, but kids showing up in droves to catch the vets anyway, a guy might as well take the money and run.